RCE in a widely used Python library (PLY) with high CVSS; could disrupt apps across industries.
CVE-2025-56005
Undocumented picklefile param in PLY yacc() enables RCE via pickle deserialization.
Is CVE-2025-56005 being exploited?
Not confirmed. CVE-2025-56005 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 18% probability of exploitation in the next 30 days.
How severe is CVE-2025-56005?
CVE-2025-56005 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-56005?
Yes. A fix has been recorded for CVE-2025-56005. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-56005 affect?
CVE-2025-56005 affects PLY Python Lex-Yacc (PLY) library, Python package ply 3.11 on PyPI. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2025-56005?
Upgrade PLY to patched version; avoid using yacc picklefile.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
RCE via unvalidated pickle deserialization in yacc('picklefile'); attacker can run code on target Python app.
Immediate action required